Comets are among the most beautiful and least understood nomads of
the night sky. To date, half a dozen of these most heavenly of heavenly
bodies have been visited by spacecraft in an attempt to unlock their
secrets. All these missions have had one thing in common: the high-speed
flyby. Like two ships passing in the night (or one ship and one icy
dirtball), they screamed past each other at hyper velocity -- providing
valuable insight, but fleeting glimpses, into the life of a comet. That
is, until Rosetta.

NASA is participating in the European Space Agency's Rosetta mission,
whose goal is to observe one such space-bound icy dirt ball from up
close -- for months on end. The spacecraft, festooned with 25
instruments between its lander and orbiter (including three from NASA),
is programmed to "wake up" from hibernation on Jan. 20. After a
check-out period, it will monitor comet 67P/Churyumov-Gerasimenko as it
makes its nosedive into, and then climb out of, the inner solar system.
Over 16 months, during which old 67P is expected to transform from a
small, frozen world into a roiling mass of ice and dust, complete with
surface eruptions, mini-earthquakes, basketball-sized, fluffy ice
particles and spewing jets of carbon dioxide and cyanide.

"We are going to be in the cometary catbird seat on this one," said
Claudia Alexander, project scientist for U.S. Rosetta from NASA's Jet
Propulsion Laboratory in Pasadena, Calif. "To have an extended presence
in the neighborhood of a comet as it goes through so many changes
should change our perspective on what it is to be a comet."

Since work began on Rosetta back in 1993, scientists and engineers
from all over Europe and the United States have been combining their
talents to build an orbiter and a lander for this unique expedition.
NASA's contribution includes three of the orbiter's instruments (an
ultraviolet spectrometer called Alice; the Microwave Instrument for
Rosetta Orbiter; and the Ion and Electron Sensor. NASA is also providing
part of the electronics package for an instrument called the Double
Focusing Mass Spectrometer, which is part of the Swiss-built Rosetta
Orbiter Spectrometer for Ion and Neutral Analysis instrument. NASA is
also providing U.S. science investigators for selected non-U.S.
instruments and is involved to a greater or lesser degree in seven of
the mission's 25 instruments. NASA's Deep Space Network provides support
for ESA's Ground Station Network for spacecraft tracking and
navigation.

"All the instruments aboard Rosetta and the Philae lander are
designed to work synergistically," said Sam Gulkis of JPL, the principal
investigator for the Microwave Instrument for Rosetta Orbiter. "They
will all work together to create the most complete picture of a comet to
date, telling us how the comet works, what it is made of, and what it
can tell us about the origins of the solar system."

The three NASA-supplied instruments are part of the orbiter's
scientific payload. Rosetta's Microwave Instrument for Rosetta Orbiter
specializes in the thermal properties. The instrument combines a
spectrometer and radiometer, so it can sense temperature and identify
chemicals located on or near the comet's surface, and even in the dust
and ices jetting out from it. The instrument will also see the gaseous
activity through the dusty cloud of material. Rosetta scientists will
use it to determine how different materials in the comet change from ice
to gas, and to observe how much it changes in temperature as it
approaches the sun.

Like the Microwave for Rosetta Orbiter, the Alice instrument contains
a spectrometer. But Alice looks at the ultraviolet portion of the
spectrum. Alice will analyze gases in the coma and tail and measure the
comet’s production rates of water and carbon monoxide and dioxide. It
will provide information on the surface composition of the nucleus, and
make a potentially key measurement of argon, which will be a big clue
about what the temperature was in the primordial solar system when the
comet's nucleus originally formed (more than 4.6 billion years ago).

An M5 flare (medium-size) associated with a coronal mass ejection
generated a fairly robust radiation storm (May 22-23, 2013). The
outburst originated from active region right near the right edge of the
Sun. After the eruption, cascades of magnetic loops spun up above the
area as the magnetic fields tried to reorganize themselves. When viewed
in profile, they put on a marvelous display of solar activity. The
images are a combination of two wavelengths of extreme ultraviolet light
(at 171 and 304 Angstroms). Credit: NASA's Solar Dynamics Observatory.

Sea water off the east coast of Greenland looked a bit like marbled paper in October 2012. The shifting swirls of white were sea ice, as observed by the Moderate Resolution Imaging Spectroradiometer (MODIS) on NASA’s Aqua satellite on October 17, 2012. In fact, this ice moved discernibly between October 16 and October 17. Thin, free-drifting ice moves very easily with winds and currents.

Each year, Arctic sea ice grows through the winter, reaching its
maximum extent around March. It then melts through the summer, reaching
its minimum in September. By October, Arctic waters start freezing
again. However, the ice in the image above is more likely a remnant of
old ice that migrated down to the coast of Greenland. Sea water is
unlikely to start freezing this far south in October.

Along Greenland’s east coast, the Fram Strait serves as an expressway for sea ice moving out of the Arctic Ocean. The movement of ice through the strait used to be offset by the growth of ice in the Beaufort Gyre.
Until the late 1990s, ice would persist in the gyre for years, growing
thicker and more resistant to melt. Since the start of the twenty-first
century, however, ice has been less likely to survive its trip through
the southern part of the Beaufort Gyre. As a result, less Arctic sea ice
has been able to pile up and form multi-year ice.

With less thick ice there is less Arctic sea ice volume, something
the researchers at the Polar Science Center at the University of
Washington have modeled from 1979 to 2012.
Their results appear in the graph above. The model indicates that ice
volume peaks in March through May of each year and reaches its lowest
levels from August through October. But while the seasonal timing of the
peaks and valleys has remained consistent since 1979, the total sea ice
volume has declined.

The thick blue line is the 1979–2000 average, and the lighter blue bands surrounding it are one and two standard deviations
from the median. The lines below the blue line are the calculated sea
ice volumes for the years since 2000. All of them fall below the median,
and almost all of them fall below two standard deviations.

The drop in sea ice volume is consistent with other observed changes
in Arctic sea ice. In terms of sea ice extent, the National Snow and Ice
Data Center and NASA reported that Arctic sea ice set a record low in September 2012.

The sun emitted a mid-level solar flare, peaking at 5:13 a.m. EST on
Jan. 7, 2014. Images of the flare were captured by NASA's Solar Dynamics
Observatory and showed that it came from an active region on the sun
that currently sports one of the largest sunspots seen in the last 10
years. Sunspots are regions of strong and complex magnetic fields on the
sun's surface.

Solar flares are powerful bursts of radiation. Harmful radiation from
a flare cannot pass through Earth's atmosphere to physically affect
humans on the ground, however -- when intense enough -- they can disturb
the atmosphere in the layer where GPS and communications signals
travel.

To see how this event may impact Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.

Swirling, stormy clouds may be ever-present on cool celestial orbs
called brown dwarfs. New observations from NASA's Spitzer Space
Telescope suggest that most brown dwarfs are roiling with one or more
planet-size storms akin to Jupiter's "Great Red Spot." "As the brown dwarfs spin on their axis, the alternation of what we
think are cloud-free and cloudy regions produces a periodic brightness
variation that we can observe," said Stanimir Metchev of the University
of Western Ontario, Canada. "These are signs of patchiness in the cloud
cover."

In a Spitzer program named "Weather on Other Worlds," astronomers
used the infrared space telescope to watch 44 brown dwarfs as they
rotated on their axis for up to 20 hours. Previous results had suggested
that some brown dwarfs have turbulent weather, so the scientists had
expected to see a small fraction vary in brightness over time. However,
to their surprise, half of the brown dwarfs showed the variations. When
you take into account that half of the objects would be oriented in such
a way that their storms would be either hidden or always in view and
unchanging, the results indicate that most, if not all, brown dwarfs are
racked by storms.

"We needed Spitzer to do this," said Metchev. "Spitzer is in space,
above the thermal glow of the Earth's atmosphere, and it has the
sensitivity required to see variations in the brown dwarfs' brightness."

The results led to another surprise as well. Some of the brown dwarfs
rotated much more slowly than any previously measured, a finding that
could not have been possible without Spitzer's long, uninterrupted
observations from space. Astronomers had thought that brown dwarfs sped
up to very fast rotations when they formed and contracted, and that this
rotation didn't wind down with age.

"We don't yet know why these particular brown dwarfs spin so slowly,
but several interesting possibilities exist," said Heinze. "A brown
dwarf that rotates slowly may have formed in an unusual way -- or it may
even have been slowed down by the gravity of a yet-undiscovered planet
in a close orbit around it."

The work may lead to a better understanding of not just brown dwarfs
but their "little brothers": the gas-giant planets. Researchers say that
studying the weather on brown dwarfs will open new windows onto weather
on planets outside our solar system, which are harder to study under
the glare of their stars. Brown dwarfs are weather laboratories for
planets, and, according to the new results, those laboratories are
everywhere.

The International Space Station Program and Orbital Sciences Corporation
have decided to postpone the launch of the Antares rocket and its
Cygnus cargo craft on the first Orbital commercial resupply mission to
the space station to no earlier than Wednesday, Jan. 8 due to the
forecast of cold temperatures for Tuesday, Jan. 7 at the launch site at
NASA’s Wallops Flight Facility in Virginia.

The forecast for Wednesday also calls for cold temperatures, but the
station program and Orbital plan to revisit the weather forecast at the
beginning of the week. The main concern with the weather is the cold
temperatures coupled with likely precipitation. Orbital says the Antares
rocket has a lower limit temperature constraint of 20 degrees
Fahrenheit.

Orbital still plans to roll out its Antares rocket to Launch Pad 0A at
Wallops on Saturday night because the weather is forecast to be
favorable at that time.
The launch time for Wednesday, Jan. 8 is 1:32 p.m. Eastern time. NASA TV coverage of launch will begin at 1 p.m.

A launch on Wednesday will result in a grapple of Cygnus by the
Expedition 38 crew aboard the station on Sunday, Jan. 12 at 6:02 a.m.
NASA TV coverage will begin at 5 a.m. Coverage of the installation of
Cygnus on the Earth-facing port of the Harmony module will begin at 7
a.m.

The sun ushered out 2013 and welcomed 2014 with two mid-level flares on
Dec. 31, 2013 and Jan. 1, 2014. Solar flares are powerful bursts of
radiation. Harmful radiation from a flare cannot pass through Earth's
atmosphere to physically affect humans on the ground, however -- when
intense enough -- they can disturb the atmosphere in the layer where GPS
and communications signals travel. This disrupts the radio signals for
as long as the flare is ongoing, anywhere from minutes to hours.

To see how this event may impact Earth, please visit NOAA's Space Weather Prediction Center at http://spaceweather.gov, the U.S. government's official source for space weather forecasts, alerts, watches and warnings.

The first flare (below) was categorized as an M6.4 and it peaked at
4:58 p.m EST on Dec. 31. The second (above) was categorized as an M9.9
and peaked at 1:52 p.m. EST on Jan. 1. Both flares emerged from the same
active region on the sun, AR1936. Imagery of the flares was captured by NASA's Solar Dynamics
Observatory, which keeps a constant watch on the sun, collecting new
data every 12 seconds.